1. Field of the Invention
The invention relates to an optical touch system, and especially relates to an optical touch system and method of multi-touch.
2. Description of the Prior Art
Touch control has been widely used and develops from single point touch control to multi-point touch control. The current multi-point touch control usually treats all touch points on a touch surface as a base of a single operation. For example, two touch points approaching or leaving away from each other will be regarded as an operation for scaling an image larger or smaller respectively. However, these touch points cannot be distinguished into different sources (for example the touches being performed by different users). In other words, no touch operations for different purposes at the same time is allowed by the current multi-point touch control, which makes the current multi-point touch control unable to deal with simultaneous interactive touches by different users. For example, a user is rotating an object while another user is writing or drawing an object at the same time. Such technique feature limits the application scope of the current multi-point touch control.